ERTH 2401 Lecture 20: Extinctions

• School: Carleton University
• Department: Earth Sciences
• Course: ERTH 2401
• Professor: Claudia Schröder-Adams

Document Summary

Andes: habitat destruction through fire, river migration, drying of wetland, eruption of volcanoes. Tombstone mark mass extinctions: end of ordovician we lose trilobites, they keep going for a while after, becoming completely extinct by the end of the permian. Shows when an animal is on the decline, does(cid:374)"t take (cid:373)u(cid:272)h to (cid:449)ipe the fe(cid:449) re(cid:373)ai(cid:374)i(cid:374)g out. Permian extinction, coming back a bit but never fully recovering. Corals almost lost at the end of permian, but they started to flourish again, would not have coral reefs if they were lost. Fish were successful all the way through, really flourishing after dinosaurs left. Look at what we have fossils of in the permian and then what is missing in the triassic: 52% of all families, over 2 mill years, at end of permian had a glaciation - sea-level drop. Incompleteness of fossil record: do not know how many species we had to begin with.